This invention relates to optical fibre transmission systems and in particular, but not exclusively, to overcoming chromatic dispersion problems therein.
Chromatic dispersion in optical fibre presents serious problems when using light sources whose spectrum is non-ideal, for example broad or multi-spectral-line. This problem has previously been resolved, at least partially, in two ways. Firstly, by operating at or close to the optical frequency at which the chromatic dispersion is a minimum, for example at a wavelength of 1.3 micron in conventional silica fiber. The frequency does not generally correspond with the frequency of minimum transmission loss and attempts to modify the fibre to shift its frequency of minimum chromatic dispersion usually result in some loss penalty. The second way of overcoming the problem is to use a source with a near ideal spectrum.